1. Field of the Invention
The present invention relates to a refrigerator which can defrost an evaporator quickly and uniformly.
2. Description of the Related Art
Generally, a refrigerator comprises an evaporator evaporating a refrigerant. The evaporator includes a refrigerant pipe in which the refrigerant flows, and the refrigerant pipe is provided in a zigzag formation from the upper part to the lower part of the evaporator, returning to the upper part from the lower part of the evaporator in a zigzag shape. Further, the refrigerant pipe is combined with a cooling fin in order to increase effectiveness of the heat exchange.
In the conventional evaporator, in order to defrost the evaporator, there is provided a heater pipe having a defrosting heater. Herein, the heater pipe is regularly arranged on the surface of the cooling fin.
Further, in the lower part of the evaporator is provided a defrosting sensor sensing a temperature of the evaporator and turning off the defrosting heater depending on the temperature sensed.
With this configuration, in the refrigerator, the defrosting heater is turned on at regular intervals, thereby defrosting the evaporator.
However, in the conventional refrigerator, when the defrosting heater is turned on, air around the cooling fin is heated by the defrosting heater arranged on the surface of the cooling fin, and high-temperature air starts defrosting the upper part of the evaporator before defrosting the lower part because the high-temperature air ascends. Therefore, there are problems in that the evaporator is not uniformly defrosted, and it takes a long time to defrost the evaporator completely considering the lower part thereof. Moreover, about the time when the lower part of the evaporator is defrosted, temperature of the upper part of the evaporator is rather high, and that makes the temperature of an upper part of the refrigerator also high. If the temperature of the upper part of the refrigerator rises enough to affect a set temperature of the inner part of the refrigerator, the food kept in the refrigerator may go bad.